[exim.git] / src / README.UPDATING
1 This document contains detailed information about incompatibilities that might
2 be encountered when upgrading from one release of Exim to another. The
3 information is in reverse order of release numbers. Mostly these are relatively
4 small points, and the configuration file is normally upwards compatible, but
5 there have been two big upheavals...
8 **************************************************************************
9 * There was a big reworking of the way mail routing works for release *
10 * 4.00. Previously used "directors" were abolished, and all routing is *
11 * now done by routers. Policy controls for incoming mail are now done by *
12 * Access Control Lists instead of separate options. All this means that *
13 * pre-4.00 configuration files have to be massively converted. If you *
14 * are coming from a 3.xx release, please read the document in the file *
15 * doc/Exim4.upgrade, and allow some time to complete the upgrade. *
16 * *
17 * There was a big reworking of the way domain/host/net/address lists are *
18 * handled at release 3.00. If you are coming from a pre-3.00 release, it *
19 * might be easier to start again from a default configuration. Otherwise *
20 * you need to read doc/Exim3.upgrade and do a double conversion of your *
21 * configuration file. *
22 **************************************************************************
25 The rest of this document contains information about changes in 4.xx releases
26 that might affect a running system.
29 Exim version 4.80
30 -----------------
32 * BEWARE backwards-incompatible changes in SSL libraries, thus the version
33 bump. See points below for details.
35 * The value of $tls_peerdn is now print-escaped when written to the spool file
36 in a -tls_peerdn line, and unescaped when read back in. We received reports
37 of values with embedded newlines, which caused spool file corruption.
39 If you have a corrupt spool file and you wish to recover the contents after
40 upgrading, then lock the message, replace the new-lines that should be part
41 of the -tls_peerdn line with the two-character sequence \n and then unlock
42 the message. No tool has been provided as we believe this is a rare
43 occurence.
45 * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2. If built
46 against 1.0.1a then you will get a warning message and the
47 "openssl_options" value will not parse "no_tlsv1_1": the value changes
48 incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
49 is infelicitous. We advise avoiding 1.0.1a.
51 "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
53 COMPATIBILITY WARNING: The default value of "openssl_options" is no longer
54 "+dont_insert_empty_fragments". We default to unset. That old default was
55 grandfathered in from before openssl_options became a configuration option.
56 Empty fragments are inserted by default through TLS1.0, to partially defend
57 against certain attacks; TLS1.1+ change the protocol so that this is not
58 needed. The DIEF SSL option was required for some old releases of mail
59 clients which did not gracefully handle the empty fragments, and was
60 initially set in Exim release 4.31 (see ChangeLog, item 37).
62 If you still have affected mail-clients, and you see SSL protocol failures
63 with this release of Exim, set:
64 openssl_options = +dont_insert_empty_fragments
65 in the main section of your Exim configuration file. You're trading off
66 security for compatibility. Exim is now defaulting to higher security and
67 rewarding more modern clients.
69 * Ldap lookups returning multi-valued attributes now separate the attributes
70 with only a comma, not a comma-space sequence. Also, an actual comma within
71 a returned attribute is doubled. This makes it possible to parse the
72 attribute as a comma-separated list. Note the distinction from multiple
73 attributes being returned, where each one is a name=value pair.
75 * accept_8bitmime now defaults on, which is not RFC compliant but is better
76 suited to today's Internet. See http://cr.yp.to/smtp/8bitmime.html for a
77 sane rationale. Those who wish to be strictly RFC compliant, or know that
78 they need to talk to servers that are not 8-bit-clean, now need to take
79 explicit configuration action to default this option off. This is not a
80 new option, you can safely force it off before upgrading, to decouple
81 configuration changes from the binary upgrade while remaining RFC compliant.
83 * The GnuTLS support has been mostly rewritten, to use 2.12.x APIs. As part
84 of this, these three options are no longer supported:
86 gnutls_require_kx
87 gnutls_require_mac
88 gnutls_require_protocols
90 Their functionality is entirely subsumed into tls_require_ciphers, which is
91 no longer parsed apart by Exim but is instead given to
92 gnutls_priority_init(3), which is no longer an Exim list. See:
94 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
96 for fuller documentation of the strings parsed. The three gnutls_require_*
97 options are still parsed by Exim and, for this release, silently ignored.
98 A future release will add warnings, before a later still release removes
99 parsing entirely and the presence of the options will be a configuration
100 error.
102 Note that by default, GnuTLS will not accept RSA-MD5 signatures in chains.
103 A tls_require_ciphers value of NORMAL:%VERIFY_ALLOW_SIGN_RSA_MD5 may
104 re-enable support, but this is not supported by the Exim maintainers.
105 Our test suite no longer includes MD5-based certificates.
107 This rewrite means that Exim will continue to build against GnuTLS in the
108 future, brings Exim closer to other GnuTLS applications and lets us add
109 support for SNI and other features more readily. We regret that it wasn't
110 feasible to retain the three dropped options.
113 Exim version 4.77
114 -----------------
116 * GnuTLS will now attempt to use TLS 1.2 and TLS 1.1 before TLS 1.0 and SSL3,
117 if supported by your GnuTLS library. Use the existing
118 "gnutls_require_protocols" option to downgrade this if that will be a
119 problem. Prior to this release, supported values were "TLS1" and "SSL3",
120 so you should be able to update configuration prior to update.
122 * The match_<type>{string1}{string2} expansion conditions no longer subject
123 string2 to string expansion, unless Exim was built with the new
124 "EXPAND_LISTMATCH_RHS" option. Too many people have inadvertently created
125 insecure configurations that way. If you need the functionality and turn on
126 that build option, please let the developers know, and know why, so we can
127 try to provide a safer mechanism for you.
129 The match{}{} expansion condition (for regular expressions) is NOT affected.
130 For match_<type>{s1}{s2}, all list functionality is unchanged. The only
131 change is that a '$' appearing in s2 will not trigger expansion, but instead
132 will be treated as a literal $ sign; the effect is very similar to having
133 wrapped s2 with \N...\N. If s2 contains a named list and the list definition
134 uses $expansions then those _will_ be processed as normal. It is only the
135 point at which s2 is read where expansion is inhibited.
137 If you are trying to test if two email addresses are equal, use eqi{s1}{s2}.
138 If you are testing if the address in s1 occurs in the list of items given
139 in s2, either use the new inlisti{s1}{s2} condition (added in 4.77) or use
140 the pre-existing forany{s2}{eqi{$item}{s1}} condition.
143 Exim version 4.74
144 -----------------
146 * The integrated support for dynamically loadable lookup modules has an ABI
147 change from the modules supported by some OS vendors through an unofficial
148 patch. Don't try to mix & match.
150 * Some parts of the build system are now beginning to assume that the host
151 environment is POSIX. If you're building on a system where POSIX tools are
152 not the default, you might have an easier time if you switch to the POSIX
153 tools. Feel free to report non-POSIX issues as a request for a feature
154 enhancement, but if the POSIX variants are available then the fix will
155 probably just involve some coercion. See the README instructions for
156 building on such hosts.
159 Exim version 4.73
160 -----------------
162 * The Exim run-time user can no longer be root; this was always
163 strongly discouraged, but is now prohibited both at build and
164 run-time. If you need Exim to run routinely as root, you'll need to
165 patch the source and accept the risk. Here be dragons.
167 * Exim will no longer accept a configuration file owned by the Exim
168 run-time user, unless that account is explicitly the value in
169 CONFIGURE_OWNER, which we discourage. Exim now checks to ensure that
170 files are not writeable by other accounts.
172 * The ALT_CONFIG_ROOT_ONLY build option is no longer optional and is forced
173 on; the Exim user can, by default, no longer use -C/-D and retain privilege.
174 Two new build options mitigate this.
176 * TRUSTED_CONFIG_LIST defines a file containing a whitelist of config
177 files that are trusted to be selected by the Exim user; one per line.
178 This is the recommended approach going forward.
180 * WHITELIST_D_MACROS defines a colon-separated list of macro names which
181 the Exim run-time user may safely pass without dropping privileges.
182 Because changes to this involve a recompile, this is not the recommended
183 approach but may ease transition. The values of the macros, when
184 overridden, are constrained to match this regex: ^[A-Za-z0-9_/.-]*$
186 * The system_filter_user option now defaults to the Exim run-time user,
187 rather than root. You can still set it explicitly to root and this
188 can be done with prior versions too, letting you roll versions
189 without needing to change this configuration option.
191 * ClamAV must be at least version 0.95 unless WITH_OLD_CLAMAV_STREAM is
192 defined at build time.
195 Exim version 4.70
196 -----------------
198 1. Experimental Yahoo! Domainkeys support has been dropped in this release.
199 It has been superceded by a native implementation of its successor DKIM.
201 2. Up to version 4.69, Exim came with an embedded version of the PCRE library.
202 As of 4.70, this is no longer the case. To compile Exim, you will need PCRE
203 installed. Most OS distributions have ready-made library and development
204 packages.
207 Exim version 4.68
208 -----------------
210 1. The internal implementation of the database keys that are used for ACL
211 ratelimiting has been tidied up. This means that an update to 4.68 might cause
212 Exim to "forget" previous rates that it had calculated, and reset them to zero.
215 Exim version 4.64
216 -----------------
218 1. Callouts were setting the name used for EHLO/HELO from $smtp_active_
219 hostname. This is wrong, because it relates to the incoming message (and
220 probably the interface on which it is arriving) and not to the outgoing
221 callout (which could be using a different interface). This has been
222 changed to use the value of the helo_data option from the smtp transport
223 instead - this is what is used when a message is actually being sent. If
224 there is no remote transport (possible with a router that sets up host
225 addresses), $smtp_active_hostname is used. This change is mentioned here in
226 case somebody is relying on the use of $smtp_active_hostname.
228 2. A bug has been fixed that might just possibly be something that is relied on
229 in some configurations. In expansion items such as ${if >{xxx}{yyy}...} an
230 empty string (that is {}) was being interpreted as if it was {0} and therefore
231 treated as the number zero. From release 4.64, such strings cause an error
232 because a decimal number, possibly followed by K or M, is required (as has
233 always been documented).
235 3. There has been a change to the GnuTLS support (ChangeLog/PH/20) to improve
236 Exim's performance. Unfortunately, this has the side effect of being slightly
237 non-upwards compatible for versions 4.50 and earlier. If you are upgrading from
238 one of these earlier versions and you use GnuTLS, you must remove the file
239 called gnutls-params in Exim's spool directory. If you don't do this, you will
240 see this error:
242 TLS error on connection from ... (DH params import): Base64 decoding error.
244 Removing the file causes Exim to recompute the relevant encryption parameters
245 and cache them in the new format that was introduced for release 4.51 (May
246 2005). If you are upgrading from release 4.51 or later, there should be no
247 problem.
250 Exim version 4.63
251 -----------------
253 When an SMTP error message is specified in a "message" modifier in an ACL, or
254 in a :fail: or :defer: message in a redirect router, Exim now checks the start
255 of the message for an SMTP error code. This consists of three digits followed
256 by a space, optionally followed by an extended code of the form n.n.n, also
257 followed by a space. If this is the case and the very first digit is the same
258 as the default error code, the code from the message is used instead. If the
259 very first digit is incorrect, a panic error is logged, and the default code is
260 used. This is an incompatible change, but it is not expected to affect many (if
261 any) configurations. It is possible to suppress the use of the supplied code in
262 a redirect router by setting the smtp_error_code option false. In this case,
263 any SMTP code is quietly ignored.
266 Exim version 4.61
267 -----------------
269 1. The default number of ACL variables of each type has been increased to 20,
270 and it's possible to compile Exim with more. You can safely upgrade to this
271 release if you already have messages on the queue with saved ACL variable
272 values. However, if you downgrade from this release with messages on the queue,
273 any saved ACL values they may have will be lost.
275 2. The default value for rfc1413_query_timeout has been changed from 30s to 5s.
278 Exim version 4.54
279 -----------------
281 There was a problem with 4.52/TF/02 in that a "name=" option on control=
282 submission terminated at the next slash, thereby not allowing for slashes in
283 the name. This has been changed so that "name=" takes the rest of the string as
284 its data. It must therefore be the last option.
287 Version 4.53
288 ------------
290 If you are using the experimental Domain Keys support, you must upgrade to
291 at least libdomainkeys 0.67 in order to run this release of Exim.
294 Version 4.51
295 ------------
297 1. The format in which GnuTLS parameters are cached (in the file gnutls-params
298 in the spool directory) has been changed. The new format can also be generated
299 externally, so it is now possible to update the values from outside Exim. This
300 has been implemented in an upwards, BUT NOT downwards, compatible manner.
301 Upgrading should be seamless: when Exim finds that it cannot understand an
302 existing cache file, it generates new parameters and writes them to the cache
303 in the new format. If, however, you downgrade from 4.51 to a previous release,
304 you MUST delete the gnutls-params file in the spool directory, because the
305 older Exim will not recognize the new format.
307 2. When doing a callout as part of verifying an address, Exim was not paying
308 attention to any local part prefix or suffix that was matched by the router
309 that accepted the address. It now behaves in the same way as it does for
310 delivery: the affixes are removed from the local part unless
311 rcpt_include_affixes is set on the transport. If you have a configuration that
312 uses prefixes or suffixes on addresses that could be used for callouts, and you
313 want the affixes to be retained, you must make sure that rcpt_include_affixes
314 is set on the transport.
316 3. Bounce and delay warning messages no longer contain details of delivery
317 errors, except for explicit messages (e.g. generated by :fail:) and SMTP
318 responses from remote hosts.
321 Version 4.50
322 ------------
324 The exicyclog script has been updated to use three-digit numbers in rotated log
325 files if the maximum number to keep is greater than 99. If you are already
326 keeping more than 99, there will be an incompatible change when you upgrade.
327 You will probably want to rename your old log files to the new form before
328 running the new exicyclog.
331 Version 4.42
332 ------------
334 RFC 3848 specifies standard names for the "with" phrase in Received: header
335 lines when AUTH and/or TLS are in use. This is the "received protocol"
336 field. Exim used to use "asmtp" for authenticated SMTP, without any
337 indication (in the protocol name) for TLS use. Now it follows the RFC and
338 uses "esmtpa" if the connection is authenticated, "esmtps" if it is
339 encrypted, and "esmtpsa" if it is both encrypted and authenticated. These names
340 appear in log lines as well as in Received: header lines.
343 Version 4.34
344 ------------
346 Change 4.31/2 gave problems to data ACLs and local_scan() functions that
347 expected to see a Received: header. I have changed to yet another scheme. The
348 Received: header is now generated after the body is received, but before the
349 ACL or local_scan() is called. After they have run, the timestamp in the
350 Received: header is updated.
352 Thus, change (a) of 4.31/2 has been reversed, but change (b) is still true,
353 which is lucky, since I decided it was a bug fix.
356 Version 4.33
357 ------------
359 If an expansion in a condition on a "warn" statement fails because a lookup
360 defers, the "warn" statement is abandoned, and the next ACL statement is
361 processed. Previously this caused the whole ACL to be aborted.
364 Version 4.32
365 ------------
367 Change 4.31/2 has been reversed, as it proved contentious. Recipient callout
368 verification now uses <> in the MAIL command by default, as it did before. A
369 new callout option, "use_sender", has been added to request the other
370 behaviour.
373 Version 4.31
374 ------------
376 1. If you compile Exim to use GnuTLS, it now requires the use of release 1.0.0
377 or greater. The interface to the obsolete 0.8.x releases is no longer
378 supported. There is one externally visible change: the format for the
379 display of Distinguished Names now uses commas as a separator rather than a
380 slash. This is to comply with RFC 2253.
382 2. When a message is received, the Received: header line is now generated when
383 reception is complete, instead of at the start of reception. For messages
384 that take a long time to come in, this changes the meaning of the timestamp.
385 There are several side-effects of this change:
387 (a) If a message is rejected by a DATA or non-SMTP ACL, or by local_scan(),
388 the logged header lines no longer include the local Received: line,
389 because it has not yet been created. If the message is a non-SMTP one,
390 and the error is processed by sending a message to the sender, the copy
391 of the original message that is returned does not have an added
392 Received: line.
394 (b) When a filter file is tested using -bf, no additional Received: header
395 is added to the test message. After some thought, I decided that this
396 is a bug fix.
398 The contents of $received_for are not affected by this change. This
399 variable still contains the single recipient of a message, copied after
400 addresses have been rewritten, but before local_scan() is run.
402 2. Recipient callout verification, like sender verification, was using <> in
403 the MAIL FROM command. This isn't really the right thing, since the actual
404 sender may affect whether the remote host accepts the recipient or not. I
405 have changed it to use the actual sender in the callout; this means that
406 the cache record is now keyed on a recipient/sender pair, not just the
407 recipient address. There doesn't seem to be a real danger of callout loops,
408 since a callout by the remote host to check the sender would use <>.
411 Version 4.30
412 ------------
414 1. I have abolished timeout_DNS as an error that can be detected in retry
415 rules, because it has never worked. Despite the fact that it has been
416 documented since at least release 1.62, there was no code to support it.
417 If you have used it in your retry rules, you will now get a warning message
418 to the log and panic log. It is now treated as plain "timeout".
420 2. After discussion on the mailing list, Exim no longer adds From:, Date:, or
421 Message-Id: header lines to messages that do not originate locally, that is,
422 messages that have an associated sending host address.
424 3. When looking up a host name from an IP address, Exim now tries the DNS
425 first, and only if that fails does it use gethostbyaddr() (or equivalent).
426 This change was made because on some OS, not all the names are given for
427 addresses with multiple PTR records via the gethostbyaddr() interface. The
428 order of lookup can be changed by setting host_lookup_order.
431 Version 4.23
432 ------------
434 1. The new FIXED_NEVER_USERS build-time option creates a list of "never users"
435 that cannot be overridden. The default in the distributed EDITME is "root".
436 If for some reason you were (against advice) running deliveries as root, you
437 will have to ensure that FIXED_NEVER_USERS is not set in your
438 Local/Makefile.
440 2. The ${quote: operator now quotes an empty string, which it did not before.
442 3. Version 4.23 saves the contents of the ACL variables with the message, so
443 that they can be used later. If one of these variables contains a newline,
444 there will be a newline character in the spool that will not be interpreted
445 correctely by a previous version of Exim. (Exim ignores keyed spool file
446 items that it doesn't understand - precisely for this kind of problem - but
447 it expects them all to be on one line.)
449 So the bottom line is: if you have newlines in your ACL variables, you
450 cannot retreat from 4.23.
453 Version 4.21
454 ------------
456 1. The idea of the "warn" ACL verb is that it adds a header or writes to the
457 log only when "message" or "log_message" are set. However, if one of the
458 conditions was an address verification, or a call to a nested ACL, the
459 messages generated by the underlying test were being passed through. This
460 no longer happens. The underlying message is available in $acl_verify_
461 message for both "message" and "log_message" expansions, so it can be
462 passed through if needed.
464 2. The way that the $h_ (and $header_) expansions work has been changed by the
465 addition of RFC 2047 decoding. See the main documentation (the NewStuff file
466 until release 4.30, then the manual) for full details. Briefly, there are
467 now three forms:
469 $rh_xxx: and $rheader_xxx: give the original content of the header
470 line(s), with no processing at all.
472 $bh_xxx: and $bheader_xxx: remove leading and trailing white space, and
473 then decode base64 or quoted-printable "words" within the header text,
474 but do not do charset translation.
476 $h_xxx: and $header_xxx: attempt to translate the $bh_ string to a
477 standard character set.
479 If you have previously been using $h_ expansions to access the raw
480 characters, you should change to $rh_ instead.
482 3. When Exim creates an RFC 2047 encoded word in a header line, it labels it
483 with the default character set from the headers_charset option instead of
484 always using iso-8859-1.
486 4. If TMPDIR is defined in Local/Makefile (default in src/EDITME is
487 TMPDIR="/tmp"), Exim checks for the presence of an environment variable
488 called TMPDIR, and if it finds it is different, it changes its value.
490 5. Following a discussion on the list, the rules by which Exim recognises line
491 endings on incoming messages have been changed. The -dropcr and drop_cr
492 options are now no-ops, retained only for backwards compatibility. The
493 following line terminators are recognized: LF CRLF CR. However, special
494 processing applies to CR:
496 (i) The sequence CR . CR does *not* terminate an incoming SMTP message,
497 nor a local message in the state where . is a terminator.
499 (ii) If a bare CR is encountered in a header line, an extra space is added
500 after the line terminator so as not to end the header. The reasoning
501 behind this is that bare CRs in header lines are most likely either
502 to be mistakes, or people trying to play silly games.
504 6. The code for using daemon_smtp_port, local_interfaces, and the -oX options
505 has been reorganized. It is supposed to be backwards compatible, but it is
506 mentioned here just in case I've screwed up.
510 Version 4.20
511 ------------
513 1. I have tidied and re-organized the code that uses alarm() for imposing time
514 limits on various things. It shouldn't affect anything, but if you notice
515 processes getting stuck, it may be that I've broken something.
517 2. The "arguments" log selector now also logs the current working directory
518 when Exim is called.
520 3. An incompatible change has been made to the appendfile transport. This
521 affects the case when it is used for file deliveries that are set up by
522 .forward and filter files. Previously, any settings of the "file" or
523 "directory" options were ignored. It is hoped that, like the address_file
524 transport in the default configuration, these options were never in fact set
525 on such transports, because they were of no use.
527 Now, if either of these options is set, it is used. The path that is passed
528 by the router is in $address_file (this is not new), so it can be used as
529 part of a longer path, or modified in any other way that expansion permits.
531 If neither "file" nor "directory" is set, the behaviour is unchanged.
533 4. Related to the above: in a filter, if a "save" command specifies a non-
534 absolute path, the value of $home/ is pre-pended. This no longer happens if
535 $home is unset or is set to an empty string.
537 5. Multiple file deliveries from a filter or .forward file can never be
538 batched; the value of batch_max on the transport is ignored for file
539 deliveries. I'm assuming that nobody ever actually set batch_max on the
540 address_file transport - it would have had odd effects previously.
542 6. DESTDIR is the more common variable that ROOT for use when installing
543 software under a different root filing system. The Exim install script now
544 recognizes DESTDIR first; if it is not set, ROOT is used.
546 7. If DESTDIR is set when installing Exim, it no longer prepends its value to
547 the path of the system aliases file that appears in the default
548 configuration (when a default configuration is installed). If an aliases
549 file is actually created, its name *does* use the prefix.
552 Version 4.14
553 ------------
555 1. The default for the maximum number of unknown SMTP commands that Exim will
556 accept before dropping a connection has been reduced from 5 to 3. However, you
557 can now change the value by setting smtp_max_unknown_commands.
559 2. The ${quote: operator has been changed so that it turns newline and carriage
560 return characters into \n and \r, respectively.
562 3. The file names used for maildir messages now include the microsecond time
563 fraction as well as the time in seconds, to cope with systems where the process
564 id can be re-used within the same second. The format is now
566 <time>.H<microsec>P<pid>.<host>
568 This should be a compatible change, but is noted here just in case.
570 4. The rules for creating message ids have changed, to cope with systems where
571 the process id can be re-used within the same second. The format, however, is
572 unchanged, so this should not cause any problems, except as noted in the next
573 item.
575 5. The maximum value for localhost_number has been reduced from 255 to 16, in
576 order to implement the new message id rules. For operating systems that have
577 case-insensitive file systems (Cygwin and Darwin), the limit is 10.
579 6. verify = header_syntax was allowing unqualified addresses in all cases. Now
580 it allows them only for locally generated messages and from hosts that match
581 sender_unqualified_hosts or recipient_unqualified_hosts, respectively.
583 7. For reasons lost in the mists of time, when a pipe transport was run, the
584 environment variable MESSAGE_ID was set to the message ID preceded by 'E' (the
585 form used in Message-ID: header lines). The 'E' has been removed.
588 Version 4.11
589 ------------
591 1. The handling of lines in the configuration file has changed. Previously,
592 macro expansion was applied to logical lines, after continuations had been
593 joined on. This meant that it could not be used in .include lines, which are
594 handled as physical rather than logical lines. Macro expansion is now done on
595 physical lines rather than logical lines. This means there are two
596 incompatibilities:
598 (a) A macro that expands to # to turn a line into a comment now applies only
599 to the physical line where it appears. Previously, it would have caused
600 any following continuations also to be ignored.
602 (b) A macro name can no longer be split over the boundary between a line and
603 its continuation. Actually, this is more of a bug fix. :-)
605 2. The -D command line option must now all be within one command line item.
606 This makes it possible to use -D to set a macro to the empty string by commands
607 such as
609 exim -DABC ...
610 exim -DABC= ...
612 Previously, these items would have moved on to the next item on the command
613 line. To include spaces in a macro definition item, quotes must be used, in
614 which case you can also have spaces after -D and surrounding the equals. For
615 example:
617 exim '-D ABC = something' ...
619 3. The way that addresses that redirect to themselves are handled has been
620 changed, in order to fix an obscure bug. This should not cause any problems
621 except in the case of wanting to go back from a 4.11 (or later) release to an
622 earlier release. If there are undelivered messages on the spool that contain
623 addresses which redirect to themselves, and the redirected addresses have
624 already been delivered, you might get a duplicate delivery if you revert to an
625 earlier Exim.
627 4. The default way of looking up IP addresses for hosts in the manualroute and
628 queryprogram routers has been changed. If "byname" or "bydns" is explicitly
629 specified, there is no change, but if no method is specified, Exim now behaves
630 as follows:
632 First, a DNS lookup is done. If this yields anything other than
633 HOST_NOT_FOUND, that result is used. Otherwise, Exim goes on to try a call to
634 getipnodebyname() (or gethostbyname() on older systems) and the result of the
635 lookup is the result of that call.
637 This change has been made because it has been discovered that on some systems,
638 if a DNS lookup called via getipnodebyname() times out, HOST_NOT_FOUND is
639 returned instead of TRY_AGAIN. Thus, it is safest to try a DNS lookup directly
640 first, and only if that gives a definite "no such host" to try the local
641 function.
643 5. In fixing the minor security problem with pid_file_path, I have removed some
644 backwards-compatible (undocumented) code which was present to ease conversion
645 from Exim 3. In Exim 4, pid_file_path is a literal; in Exim 3 it was allowed to
646 contain "%s", which was replaced by the port number for daemons listening on
647 non-standard ports. In Exim 4, such daemons do not write a pid file. The
648 backwards compatibility feature was to replace "%s" by nothing if it occurred
649 in an Exim 4 setting of pid_file_path. The bug was in this code. I have solved
650 the problem by removing the backwards compatibility feature. Thus, if you still
651 have "%s" somewhere in a setting of pid_file_path, you should remove it.
653 6. There has been an extension to lsearch files. The keys in these files may
654 now be quoted in order to allow for whitespace and colons in them. This means
655 that if you were previously using keys that began with a doublequote, you will
656 now have to wrap them with extra quotes and escape the internal quotes. The
657 possibility that anybody is actually doing this seems extremely remote, but it
658 is documented just in case.
661 Version 4.10
662 ------------
664 The build-time parameter EXIWHAT_KILL_ARG has been renamed EXIWHAT_KILL_SIGNAL
665 to better reflect its function. The OS-specific files have been updated. Only
666 if you have explicitly set this in your Makefile (highly unlikely) do you need
667 to change anything.
669 ****